Clark lewis



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PEI-EH5. PHOTO LITHQGRAPHER. WASHINGTON. D. I.

7 side view of the same valves.

UNITED STATES PATENT OFFICE.

CLARK LEWIS, OF OASSVILLE, ASSIGNOR TO THE LEWIS COUNTER- PRESSURE LOOOMOTIVE'OOMPANY, OF \VATERVILLE, N. Y.

STEAM-BRAKE.

SPECIFICATION forming part of Letters Patent No. 228,821, dated June 15, 1880.

Application filed October 30, 1879.

To all whom it may concern:

Be it known that I, CLARK LEWIs, of Cassville, in the county of Oneida and State of New York, have invented certain new and useful Improvements in Steam Brakes; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to lettei of reference marked thereon, which form a part of this specification.

My invention consists of improvements in steam-brakes for locomotive-engines; and the object is to hold back, brake up, or entirely stop a train of cars by means of a counterpressure of steam on the pistons.

Figure 1 is a side elevation of this device as applied to a locomotive. Fig. 2 is an elevation of the same as viewed from the inside of the frame. Fig. 3 is a front elevation of the throttle and governing valves. Fig. 4 is a Fig.5 is a vertical section on line a" 00 in Fig. 4. Fig. 6 is a vertical section on line 2 z in Fig. 3.

In Figs. 1, 2, and 3 A is the frame; B, the boiler; (J, the smoke-arch, andD the cylinder. dis the steam-chest, which, in Figs. 1 and 2, is shown in sections with the slide-valves a and e in their proper positions.

The object of the principal portion of the mechanism shown in Figs. 1 and 2 is to operate the valves a and e.

In Figs. 1 and 2 E is a rock-shaft, having upon its outer end an arm, F, which extends both above and below the rock-shaft E. This arm has a vibratory motion imparted to it by the arm 6 on the inner end of the rock-shaft E, rod f, slide G, and the ordinary locomotivelink 9 and eccentrics g. The slide G runs in suitable bearings on the insideof the frame A, and carries a stud, through which a connection is made with the link 9. i

On the arm F is placed a slide, H, which moves freely up and down. To this slide is pivoted the jointed valve-rod a of the valve a. This slide is moved, as desired, on the arm F by the tumbling shaft I, on which are fixed the arms J and K. The arm K is connected with the valve-rod a by short rod 10. From the upper end of arm J rod J leads to the cab, and is pivoted to the. hand lever 70. By throwing the hand-lever k forward arm K is raised, and with it the end of the valve-rod a and slide H. The upper and lower ends of arm F vibrating in opposite directions, raising the slide H to the upper end of the arm F, reverses the movement of slide-valve a. Motion is imparted to valve 0 by jointed valverod 0, having at its outer end the yoke L, which incloses therock-shaft E immediately inside of the arm F. Rod 0 is connected to arm K by rod 1. Yoke L is of such form that when it is raised or lowered by arm K the valve 0 is moved backward or forward the width of the steam-port. When yoke L is raised to the position shown in Fig. 2 valve 0 is moved so that its ports register with the cylinder-ports, and yoke L, closely embracing the shaft E, fixes the valve firmly in that position, when it becomes simply a valve-seat. When yoke L is lowered to the position shown in Fig. 1 valve 0 is so moved as to close the steam-ports to the cylinder Fig. 2 shows the several parts in the proper positions for drawing the train. Fig. 1 is a position for working the counter-pressure attachments.

In the upper end of yoke L is a recess, M, and when the yoke L is lowered to the position shown in Fig. 1 a cog, N, on the upper side of rock-shaft D, engages in the recess M. The recess M being wider than the thickness of the cog N, the vibration of rock-shaft E imparts an intermittent reciprocating motion to valve 6 equal to two-thirds of the breadth of the steam-ports. The object of the pause in the motion of the valve 0 is to'allow the steam ahead of the piston on the return stroke to pass out through its ports.

The exhaust-steam passes from the cylinder through exhaust ports and pipes O, and through ports 0 in the throttle-valve V, which is placed on the floor of the smoke-arch. This throttle-valveV is composed of a case, in which a plug, I, of peculiar construction,is rotated by the arm 19 on its front end, rod 19, arm Q, rockshaft R, arm It, and rod S, pivoted to arm J. The plug P is cut away on its two sides, leaving a web, T, in the center, and giving free passage for the exhaust steam when the several parts are in the positions shown in Figs. 2, 3, and 5. When thrown in the position shown in Fig. 1 the plug P is given-one-fourth of a revolution, placing the web T horizontally across and closing the ports 0, as shown in Fig. 6 and by dotted lines in Fig. 5, at the same time opening communication below the plug P from one cylinder to the other, thus securing equal pressure in both.

From beneath the web T an opening, t, is made through the end of the pln P to the external air. To this opening is fitted the regulatingvalve n. This valve is kept in place by the rock-shaft W, having at its inner end a short arm, Y, which is pivoted to the back of the regulating-valve u, and on its outer end the arm Y. From the upper end of Y the hand-rod Y leads to the cab, where itis hooked up, as desired. A spring, S, is placed on the hand-rod Y, outside of the arm Y, to enable the arm to yield to the pressure on regulatingvalve u. The exhaust passages 0 being closed by the turning of plug P, the exhauststeam can only escape by forcing outward the regulating valve u, and the counter-pressure of the steam upon the piston is regulated by giving greater or less tension to the regulating-valve u by means of the hand -ro(l Y", spring S, arm Y, rock-shaft \V, and arm Y.

When drawing a train the several parts are placed in position shown in Figs. 2, 3, 4, and 5, when the valve 0 is fixed and the steam exhausts directly to the smoke-stack in the ordinary way. When the counter-pressure is desired the several parts are placed in the positions shown in Figs. 1 and (i and by the dot ted lines in Fig. 5, by which the position of valve to is reversed, valve 0 set in motion, which admits steam before the piston, the exhaustpassages closed by the one-fourth revolution of the plug P, and any desired counter-pressure secured by drawing in the hand-rod Y.

It will be observed that no shifting of the link g is required for this operation, the link 9 being only used to reverse the engine in the ordinary way.

Having thus described my invention, what I esteem as new, and desire to secure by Letters Patent, is-- l. The combination, with the valve 6 and valve-rod c, of the rock-shaft E, provided with cog N, and yoke L, provided with slot M, substantially as set forth.

2. The combination, with the valves to and c and valve-rods a c, of the yoke L, rockshaft E, cog N, rock-arm F, and slide H, and devices for imparting simultaneous movement to the yoke and slide, substantially as set forth.

The combination, with the steam-cylinders, exhaust-pipes, and exhaust-nozzle of a locomotive, of a plug-valve, P, constructed substantially as described, whereby the exhaust-steamniay be directed to the smokestack or the valve turned to form a steampassage between the two cylinders, substantially as set forth.

4. The combination, with the steam-cylinders, exhaust-pipes, and exhaust-nozzle of a locomotive, of a plug-valve, P, constructed to direct the exhaust into the stack or cut off communication with the stack and form a steam-passage through the nozzle between the cylinders, and aregulating-valve, a, connected with the nozzle, substantially as set forth.

5. In a steam-brake, the combination, with eXhaust-nozzle, plug-valve P, and regulatingvalve u, of the valves to and c, and intervening mechanism, substantially as set forth.

6. The COIIlbll'lELhlOll, with the exhaust-nozzle, of the plug-valve P, having regulatingvalve a located in one end thereof, substantially as set forth.

In testimony that I claim the foregoing I have hereunto set my hand this 22d day of October, 1879.

CLARK LEWIS.

Witnesses FRANCIS H. TERRY, ALoNzo BURDICK. 

